Fisher Scientific* UriSystem* Refractometer - For urine; Specific gravity: 1.000 to 1.050;3117599 : Each Description Easy to use with a sharp, clear image of the Specific Gravity and Refractive Index scales Specific Gravity scale reads from 1.000 to 1.050 in increments of 0.005; RI scale is from 1.333 to 1.356 in 0.001 increments